Reliability for personal authentication is important for security in a networked society. Many physiological characteristics of humans such as biometrics, are typically time invariant, easy to acquire, and unique for every individual. Biometric features such as face, iris, fingerprint, hand geometry, palmprint, and signature have been suggested for security to control access.
The reliability of personal identification using the face is currently low as there are problems relating to pose, lighting, orientation and gesture. Fingerprint identification is widely used for personal identification because it works well in most cases. For some cases, however, it is difficult to acquire fingerprint features such as minutiae for people including manual laborers and elderly people. As a result, other biometric characteristics are receiving increased attention. However, typical 2D palmprint systems are more prone to spoof attacks compared to fingerprint systems that require special materials and sometimes special skills.